Is this correct?
When I crossed last year in September I cam from Al Marka to Djibouti but there is deffinatly NO ferry doing this trip. I crossed on a small wooden dhow with my motorbike. You may be lucky enough to get a larger boat from Aden but please don't hold your breath. I was told that there was no ferry at all when I was in Aden!
Anyway, which ever way you get across, good luck!